.\" Copyright (C) 2022 Jens Axboe <axboe@kernel.dk>
.\"
.\" SPDX-License-Identifier: LGPL-2.0-or-later
.\"
.TH io_uring_buf_ring_cq_advance 3 "May 18, 2022" "liburing-2.2" "liburing Manual"
.SH NAME
io_uring_buf_ring_cq_advance \- advance index of provided buffer and CQ ring
.SH SYNOPSIS
.nf
.B #include <liburing.h>
.PP
.BI "int io_uring_buf_ring_cq_advance(struct io_uring *" ring ",
.BI "                                 struct io_uring_buf_ring *" br ",
.BI "                                 int " count ");"
.fi
.SH DESCRIPTION
.PP
The
.BR io_uring_buf_ring_cq_advance (3)
commits
.I count
previously added buffers to the shared buffer ring
.IR br ,
making them visible to the kernel and hence consumable. This passes ownership
of the buffer to the ring. At the same time, it advances the CQ ring of
.I ring
by
.I count
amount. This effectively bundles both a
.BR io_uring_buf_ring_advance (3)
call and a
.BR io_uring_cq_avance (3)
into one operation. Since updating either ring index entails a store memory
barrier, doing both at once is more efficient.

.SH RETURN VALUE
None
.SH SEE ALSO
.BR io_uring_register_buf_ring (3),
.BR io_uring_buf_ring_add (3),
.BR io_uring_buf_ring_advance (3)
